By Eduardo Baptista BEIJING (Reuters) – Beijing has stepped up security and COVID curbs and decorated the capital Beijing with red political banners as it gears up for a Communist Party congress where President Xi Jinping is poised to become China’s most powerful leader since Mao Zedong. The 20th party congress, which opens on Oct. 16, occurs every five years and brings together 2,300 party members, mostly behind closed doors, at the vast Great Hall of the People on Tiananmen Square. Beijing has hired extra security personnel, according to procurement tenders, including 42 guards to keep 24-ho…